As the populations of our cities and towns increase, so does the need to provide multi-functional venues or stadia where we can watch, play or participate in a variety of sports or other activities. Increasingly these days a sports stadium may double as a football pitch, hockey field and athletics track, whereas the local racecourse also caters for both dog racing and horse racing. In our larger cities, international-standard stadia are used for major sports fixtures, parades, even concerts.
Whilst the design of such multi-purpose venues primarily focuses on the needs of spectators, the wear and tear on the activity surface contained within the venue can be a ground-keeper's nightmare. For a number of sports such as cricket, tennis or football, there is constant pressure to maintain the playing surface in the best condition possible and quite often the ranking of, for example, a football stadium as a fixture will be judged not only on its physical design, but also the quality of its playing surface.
Both single and multi-purpose activity surfaces are subject to wear and tear through use and exposure to the elements. Some areas of an activity surface will wear at a different rate than other areas, and a good example of this is the region in a football pitch around the so called ‘six yard box’, which often will be worn down before any other part of the pitch. Exposure to the elements further complicates the upkeep of an activity surface and, despite the best endeavours of all concerned, some areas can never be returned to a satisfactory state. Attempts to solve this problem by enclosing the activity surface are not always successful, especially where the activity surface is turfed as the resulting environment may be inhospitable to the turf surface.
In addition, it may be desirable to be able to easily and quickly reconfigure a part or all of an activity surface such that the function of the reconfigured area can be altered. For example, a stadium surface (or a portion of same) could be changed from a turfed surface used for football to an artificial surface used for hockey. Ideally, such a transformation should be able to be effected quickly, and the reconfigured surface as a whole should be as uniform as possible.
Another type of activity surface which is of interest is a racetrack. As racecourses occupy considerable areas, they often have points of the racetrack at which a crossing is provided. The crossing is usually in the form of a road which is used by vehicles for the vast majority of time throughout the year. However, shortly before a race meeting, the crossing is closed to road vehicles and measures are taken to make the tarmac road surface temporarily simulate the natural surface of the racetrack. These measures include placing coconut matting on the tarmac road surface and overlaying this with natural turf. In addition, a running rail of the racetrack is connected across the road for the racehorses' guidance. Once the race meeting is over, the added section of running rail is taken down and the coconut matting and the sections of turf placed thereon are simply removed from the tarmac road surface so that the crossing can be used by road vehicles once again.
Horses racing on the racetrack can be quite sensitive to changes in the ‘going’ of the racetrack ground. On approaching the crossing, they feel the difference in the way in which the ground deflects under their hoofs. In the past, most horses have simply got used to this difference and though experience they learn how to deal with this change in hardness of the ground so as not to be startled by it. For young horses this has however, always been a problem which causes adverse reaction in the horse's behaviour. For example, some horses try to jump the road and other simply pull up. Recently, some young horses have actually broken their hoofs on the harder road crossing section of the racetrack.
One possible way of overcoming this problem is to make the access via both the road and the racetrack continuous. This can be achieved by building a road tunnel or underpass such that the vehicles can pass under the flat continuous racetrack at the crossing. The major difficulty with this proposal is that of cost. Building such a road tunnel or underpass is extremely expensive and also requires local planning permission to be obtained.
Many attempts have been made to provide systems and methods to allow an activity surface or part of the same to be reconfigured. The most common solution has been to provide a multitude of mobile sections of the activity surface, which are positioned where required and joined together. However, the present inventors have realised that there are a number of disadvantages with existing systems and methods which, for example, make them unsuitable for solving the problems associated with racetrack crossings. Some of these known systems and their known implementations are described below.
Turf moving systems are known for creating turfed sports surfaces such as football pitches. One such system is described in International patent application WO-A-92/05690. This document describes a system in which a plurality of mobile turf units are provided each containing turf growing medium and a turf surface. Each of the units is stored in a growing position and then moved into a stadium and assembled together for use. However, the difficulty with these types of turf moving systems is that the units are designed to be replaceable infrequently, namely that they are semi-permanent. More particularly, once the turf units have been assembled together, the turf and soil at the edges of the turf units are tended to grow as a single continuous surface with the turf roots binding the edges together in a semi-permanent fashion to provide the required integrity of contacting turf unit edges. Accordingly, these types of systems are not designed to be readily reconfigurable. Furthermore, the units' assembly can take a long time as the units have to be physically connected together and then the upper turfed surface constructed by the addition of topsoil and turf.
GB-A-2 138 690 describes a reconfigurable turf tray moving system. A plurality of turf trays are provided, which are mobile by floatation on compressed air, and can be arranged to make up a turfed sports pitch. Each turf tray is provided with a pliable plastics edging which is supposed retain the integrity of the playing surface. However, in practice, as the pliable edging has different deformation characteristics to natural turf and soil, the pliable edging can interfere with the performance of the sports surface. More specifically, a natural turfed soil surface varies in its deformation characteristics with weather conditions. For example, the water content of the soil changes the hardness of the soil with changes in temperature such that the soil can become quite hard with cold frosty weather and can become very soft with relatively warm wet weather. However, the pliable edging used does not have this variation in its deformation characteristics such that in some weather conditions, the performance of the sports surface at the edging is too different to that of the surrounding turf to be acceptable.
Another reconfigurable turf tray moving system is known from International patent application WO-A-95/33890. A utility surface such as a turfed playing surface can be constructed from a plurality of turf trays. Each of the turf trays is provided on air bearings and several such trays can be moved into position to create a turfed sports surface. The edges of the turf trays when mated together are provided below the turfed surface. This is achieved by having pivotable edging which can be raised for providing support of the turf and soil during a growth phase and lowered when the turf tray is to be connected to another turf tray.
The types of turf trays described in WO-A-95/33890 are not suitable for use in reconfigurably closing a gap in a pathway such as a racetrack or, in fact, for reconfigurably closing a gap between any two fixed opposing edges of an activity surface. This is because in order to move a movable tray into its final position within a gap, an excessive amount of rubbing is caused between the edges of the tray and those of the fixed activity surface which leads to an unacceptable amount of wear at the join between the activity surface and that of the tray surface. More specifically, excessive wear can lead to dangerous gaps in the activity surface appearing. Furthermore, the prior art turf tray systems are not designed to be moved frequently and as such there is no appreciation of the problems of maintaining a turf edge which has to be engaged and disengaged from the edges of the activity surface quickly and repetitively without substantial deterioration.
GB 319 472 describes a system in which flat indoor or outdoor tracks and racing surfaces or portions of same are converted to a banked or other type of track by means of portable or removable sections or receptacles. The sections are arranged on top of the original track surface and a new track surface is constructed thereon using the sections, which may be bolted or fixed together to form a complete arrangement of any desired design or form of surface. This type of system is at least semi-permanent and is not suitable for the frequent replacement of a section of the original activity surface. In addition, the resulting arrangement is not able to be removed and replaced relatively quickly, and the construction of the arrangement on top of the original activity surface is likely to damage the latter, which is unacceptable.
U.S. Pat. No. 4,281,831 describes a movable dirt tray which can be used to convert a continuous horse racetrack into a continuous dog racetrack and has particular application where horse racetracks are combined with dog racetracks so that dog races may be held during the period when the horses are not racing. A pair of portable sections for a dog racetrack are provided and positioned relative to fixed sections of the racetrack. Movement of the sections is achieved by providing each section with at least one laterally extending axle which engages with a pair of wide tread rollers or wheels. Each section can be connected to a power plant via a winch and cable system such that when required, the portable sections can be automatically aligned and joined with the fixed sections to form a continuous racetrack. The sections are joined by way of a number of hingedly mounted plates or spans, and any gaps between the sections are filled or covered by sand, silt or other natural or man-made material which forms part of the track surface.
The quality of the activity surface is not suitable for use in relation to turfed activity surfaces or where a seamless join between the sections is required. Furthermore, as with GB 319 472 this system has the disadvantage of not being readily reconfigurable, and the movement of the sections across the horse racetrack may result in damage to same, which is unsatisfactory.
GB-B-2 290 239 describes an element for use in constructing a utility or activity surface, such as a football pitch. To solve the problem of wear and tear on such large surface areas, coupled with exposure to the elements, a tray-shaped member element is used to construct a utility surface. The element has at least one upstanding side wall with a detachable or movable upper portion and a flexible lining disposed within the element. The side wall has an upper portion which is pivotable (foldable) between a raised ‘operative’ position and a lowered ‘inoperative’ position. The purpose of this is to secure a retaining structure for the soil filling of the tray during the growth of the turf, particularly at the periphery of the tray, and to provide a continuous turf surface when the elements are put together to form the activity surface. The upper portions of the tray are retained in the operative position whilst the tray is in storage or when it is being transported to or from a storage area. However, the system is not designed to be used for closing a gap as the edge profile of each element would degrade unacceptably if used in this manner. The use of a compressed air source to create a fluid cushion between the tray-shaped member elements and an underlying support surface is also described, by which the elements may be moved from a storage position and positioned as desired to form the activity surface, and a method of forming a games pitch for use using the aforementioned features.
International patent application WO-A-96/12533 refers to turfing systems for stadia and describes a turf unit which has a fence hingeably connected to a growing pan. The outer periphery of the fence extends beyond the outer periphery of the growing pans such that when the turf units are assembled to create a playing surface, large open volumes are created beneath the peripheries of the adjacent growing pans for storing the fence sections and allowing good water drainage of the playing surface. However, an activity surface formed using such turf units is not reconfigurable without damage to the activity surface itself and is also unsuitable for closing a gap in an activity surface.
Accordingly, as mentioned before the existing turf tray moving systems are not suitable for closing a fixed gap in an activity surface and so could not be used as part of a reconfigurable racetrack crossing.
Therefore, it is desired to provide a practical solution to the racetrack crossing problem and also to eliminate or at least substantially reduce the disadvantages of the existing movable activity section systems via the present invention.